title: Homothorax plays autonomous and nonautonomous roles in proximodistal axis formation and migration of the Drosophila renal tubules.
abstract: The Drosophila Malpighian tubules (MpTs) serve as a functional equivalent of the mammalian renal tubules. The MpTs are composed of two pairs of epithelial tubes that bud from the midgut-hindgut boundary during embryogenesis. The MpT primordia grow, elongate and migrate through the body cavity to assume their final position and shape. The stereotypic pattern of MpT migration is regulated by multiple intrinsic and extrinsic signals, many of which are still obscure. In this work, we implicate the TALE-class homeoprotein Homothorax (Hth) in MpT patterning. We show that in the absence of Hth the tubules fail to rearrange and migrate. Hth plays both autonomous and nonautonomous roles in this developmental process. Within the tubules Hth is required for convergent extension and for defining distal versus proximal cell identities. The difference between distal and proximal cell identities seems to be required for proper formation of the leading loop. Outside the tubules, wide-range mesodermal expression of Hth is required for directing anterior migration. The nonautonomous effects of Hth on MpT migration can be partially attributed to its effects on homeotic determination along the anterior posterior axis of the embryo and to its effects on stellate cell (SC) incorporation into the MpT.
authors.affiliation: Department of Genetics, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel.
authors.forename: Adi
authors.initials: A
authors.lastname: Zohar-Stoopel
authors.forename: Nitzan
authors.initials: N
authors.lastname: Gonen
authors.forename: Mohammed
authors.initials: M
authors.lastname: Mahroum
authors.forename: Doreen S
authors.initials: DS
authors.lastname: Ben-Zvi
authors.forename: Hila
authors.initials: H
authors.lastname: Toledano
authors.forename: Adi
authors.initials: A
authors.lastname: Salzberg
mesh_terms: D000818:Animals; D004330:Drosophila; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007684:Kidney Tubules / Q000196:embryology* / Q000378:metabolism*; D008648:Mesoderm / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D014157:Transcription Factors; C083405:exd protein, Drosophila
keywords: extradenticle; homothorax; meis proteins; proximodistal axis; renal tubules; tubule migration